populate_sdk_base.bbclass: fix SDK relocation issues

populate_sdk_base.bbclass: fix SDK relocation issues

The problem appears if multiple setup environment scripts are found. In
order to find only the script we're interested in, I removed globbing in
matching pattern with ${REAL_MULTIMACH_TARGET_SYS} that will be expanded
to the correct string.

Also, fix a problem when changing the scripts/configs. The grep pattern
matched also files that contained "text" in their name.

(From OE-Core rev: d81768560676da201fd730ae3930b080ab8c5c75)

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>